Exhaust manifold



Dec. 1924. 1,517,634

H. JUNKERS EXHAUST MANI FOLD Filed Sept. 8. 1920 Patented Dec. 2, 1924.

UNITED STATES HUGO JUNKERS, 0F DESSAU, GERMANY.

EXHAUST MANIFOLD.

Application filed September 8, 1920.

1 0 all-whom it may concern:

Be it known that I, How J UNnEns. a citizen of the German Empire, residing at Dessau, (Jrermany, have invented certain new and useful Improvements in Exhaust Manifolds, of which the following is a specification.

My invention relates to exhaust manifold. In the case of motors having a large output it will generally be found necessary to cool the exhaust manifold in order to prevent their destruction by the hot. gases of combustion. In the case of stationary or marine motors it is for this reason already known to surround the exhaust manifold, as Well as the exhaust piping, with a jacket traversed by water. Such means are however hardly suitable for aircraft motors owing to the increase of weight which would thereby be entailed.

According to the present invention I pro vide the exhaust manifold with an air jacket surrounding it and so constructed as to secure a thorough cooling thereof at all its parts. To this end, the air admission ports are arranged so as to be virtually distributed over the surface of the cooling jacket, in consequence of which arrange ment particularly those parts of the exhaustmanifold which are chiefly exposed to the action of the heat developing combustion gases and which are therefore mostly in need of cooling, will be directly swept to the utmost extent possible by cooling air. Such parts will be found to notably exist where the exhaust gases are hottest, i. e. at the connection pipes, or where, owing to a change of direction, or an impinging on walls, or where several gas currents happen to meet, powerful eddies are produced. Moreover, in the case of such an arrangement it is very easy to avoid the formation of dead corners where no cooling air could enter. Again, the paths for the cooling air may be considerably shortened (which could hardly be done in the case of the known forms of arrangement) seeing that now every particle of the cooling air is drawn off in the centre of the exhaust manifold, or even at several points distributed across the surface thereof. It will, however, be readily understood that whenever the path to be traversed by the cooling air is thus shortened the resulting cooling action will be a far more powerful one for the simple Serial No. 409,022.

reason that the cooling air has now less opportunity to absorb heat, and also because the resistances to the flow being lessened. the cooling air now assumes a greater speed.

Notwithstanding, with a view to effecting a still further improvement in the admisslon of cooling air, there may be arranged in the space intermediate the cooling jacket and the exhaust manifold, special guide faces which would serve to secure a uniform distribution of the air current across the entire surface of the exhaust manifold, and the reliable ventilation of particularly exposed parts. If these guide faces be now connected to the walls of the exhaust manifold so as to enable a conduction of heat. to be established then they will in addition constitute an effective increase in the means serving to draw off the heat from the surface of said exhaust manifold.

In order to render the motor conveniently accessible in the case of an arrangement of the exhaust manifold within the motor shell, and also with a view to enabling the exhaust manifold to be quickly built in and just as quickly removed. a portion of the motor shell is hinged. the exhaust pipings being conducted through this said hinged portion. The parts of the exhaust piping arranged outside the motor shell are connected to the hinged portion and when said portion is turned down, i. e. closed, either bear down upon the edges of the ports arranged along the exhaust. manifold, or else they are fixed to this latter. and provided with such a bend that the hinged portion of the shell may be opened or closed without being in any way impeded by their presence.

In the drawings aflixed to this specification and forming part thereof. an exhaust manifold embodying my invention is shown by way of example. In the drawings:

Fig. 1 is an elevation of an aircraft motor provided with an exhaust manifold arranged in accordance with this invention, the exhaust manifold itself being shown in a sectional view taken on lines I-I in Fig. 2,

g. 2 a plan of the arrangement, the shell of the exhaust manifold being shown in a section taken along line IIII in Fig. 1,

Fi 3 a sectional side elevation along line IIIIII in Fig. 1 and Fig. 4 a per- Ill) velops it and which is composed of stationary walls 2 and a hinged cover 3. Within this said shell there is arranged the exhaust manifold 5, with the result that it can create no objectionable resistance during flight. Around the exhaust manifold is disposed, but so as to-maintain a suitable space on all sides, a jacket 6 serving for the conduction of the current of cooling air intended to sweep across the exhaust manifold.

The admission of-the-air to the space separating the exhaust manifold and its jacket is effected in the example, shown through ports 9 formed in jacket 6 and surrounding the connection pipes 8 of the exhaust manifold, in other Words at the very points where the exhaust gases are the hottest. The cooling air passes out through port 10 surrounding the exhaust pipe 7 arranged in the centre of the exhaust manifold.

The current of cooling air is produced partly by means of'dynamic pressure exerted by the air entering at the front end of the motor shell through the radiator 4' arranged at that point, partly through the suction action of the pipe connection 12 which is bevelled off at its rear end and surrounds the exhaust pipe 7 in the manner of a nozzle. This pipe connection 12 is connected to the hinged cap or cover 3 and when this latter is closed bears down on the opening of port 10 in such disc that the .coolingair may freely pass through the pipe connection 12. The exhaust pipe 7 is bent alon the arc of a circle descrlbed around the ulcrum 11 of the cap or cover 3 in order to allow of this latter being freely closed and opened. The position of the cover 3 when open, is indicated in dotted lines in shortest path when sweeping across the space intermediate the shell and the exhaust manifold, the said air being now rather forced to traverse the exhaust manifold in its entirety and in particular to effectively ventilate those very parts of said exhaust manifold most liable to become overheated.

I claim:

1. In an exhaust manifold in combination, a cooling air jacket surrounding said manifold and air "admission ports distributed over said jacket.

2. In an exhaust manifold in combination, a cooling air jacket surrounding said manifold and air admission ports distributed over said jacket in close proximity to the exhaust pipes of the cylinders.

3. In an exhaust manifold in combination, a cooling air jacket surrounding said manifold and air admission and exhaust ports distributed over said jacket.

4. In ,an exhaust manifold in combination, a cooling air jacket surrounding said manifold, air admission ports distributed over said jacket and an air outlet near the centre of said manifold.

5. In an exhaust manifold in combination, a cooling air jacket surrounding said manifold, air admission ports distributed over said'jacket and air uiding surfaces between said manifold and said enevelope.

In testimony whereof I affix my signature.

HUGO J UNKERS. 

